1. Field of the Invention
The present invention relates to a leadframe enhancing molding compound bondability and a package structure thereof, and more particularly, to a leadframe for enhancing bondability with the molding compound encapsulating a semiconductor package, and to a structure of the semiconductor package.
2. Description of Related Art
Referring to FIG. 1A, a cross-sectional view illustrating a conventional semiconductor package, a semiconductor chip 91 is fixed on a conventional leadframe 9, where the semiconductor chip 91 is electrically connected with the leadframe 9 through gold wires 92. The semiconductor chip 91, the gold wires 92, and the leadframe 9 are encapsulated by molding compound 93 such that the purpose of protection and insulation can be achieved. However, along with continuous development of technology, electronic components have been developed rapidly toward the tendency of light, thin, short, and small. Therefore, in response to the continuous size reduction of the electronic components, the size of the leadframe 9 is also reduced continuously. As a result, the contact area between the leadframe 9 and the molding compound 93 becomes restricted.
Since the contact portion between the leadframe 9 and the molding compound 93 is smooth, and since the contact area between the leadframe 9 and the molding compound 93 reduces greatly, the bondability therebetween decreases significantly. This will worsen delamination between the leadframe 9 and the molding compound 93, or even result in singulation which causes detachment of leads, seriously affecting the product yield during a manufacturing process. It is noted that quad flat non-lead packages become a mainstream of package manufacturing processes. A quad flat non-lead package is characterized in that external leads are absent, namely, external leads for electrically connecting outside, as used in a conventional quadrangular QFP semiconductor package, are not formed therein. This makes it possible for the QFP package to reduce the size of the semiconductor package, though the phenomenon of delamination between the leadframe and the molding compound gets even worse.
Now referring to FIG. 1B, a cross-sectional view illustrating another conventional semiconductor package, along with continuous progress of manufacturing technique, a conventional leadframe 94 has been developed to have a “T” shape or inverted “L” shape, characterized in that through a T-shape or inverted-L-shape extension platform 95, the bondability between the leadframe 94 and a molding compound 96 can be increased. Nevertheless, in spite of the fact that this measure may somewhat improve the bondability, such improvement is considered insufficient, and the situation of delamination can still take place easily.